Upper airway disorders in patients can result in a variety of difficulties, such as obstructive sleep apnea, snoring, labored breathing, oxygen starvation, and the resulting physical impairments arising from such disorders including headaches, chronic fatigue, sleep problems, and problems chewing, swallowing and speaking. The pathogenesis of airway obstruction that characterizes upper airway disorders can include both anatomic and functional abnormalities of the upper airway that result in increased air flow resistance. Such abnormalities may include narrowing of the upper airway due to suction forces created during inspiration, the effect of gravity pulling the tongue back to oppose the pharyngeal wall, and insufficient muscle tone in the upper airway dilator muscles, among others. It is also believed that excessive soft tissue in the anterior and lateral neck, as commonly observed in obese persons, can apply sufficient pressure to internal structures to narrow the upper airway and restrict air flow.
The tongue is normally maintained in a somewhat forward position under autonomic nervous control, which in turn is effected by the medulla of the brain. This autonomic control may not be maintained in a person who is sleeping, semi-conscious, unconscious or under heavy sedation. When one's head is oriented with the mouth pointing upwards, should the tongue become too relaxed it can fall back towards the throat, reducing the flow of air in to the lungs or even closing the airway. If a severe closure condition is not corrected within several minutes, this can reduce oxygen saturation in the brain, and, if left uncorrected, can lead to irreversible brain damage or even death. In order for the tongue to be able to stay forward, it is important for the tension on the major muscle of the tongue (the genioglossus muscle) and the pharyngeal muscles to be maintained.
Oral appliances are sometimes used in order to open the airway behind the tongue and allow easier breathing through the nose and mouth. For example, U.S. Pat. No. 5,752,822 to Robson discloses a mandibular appliance which has tongue positioning extensions designed to elevate the tongue and move it forward to reduce or relieve symptoms related to upper airway disorders. While useful, this device acts upon the tongue only and does not address other portions of the mouth and airway. U.S. Pat. No. 7,328,705 to Abramson discloses an anti-snoring device comprising the combination of an intraoral nasal dilator and a mandibular repositioner. This device fits over the mandibular teeth and is bulky. U.S. Pat. No. 5,794,627 to Frantz et al. discloses an orthotic that extends an elastic band between top and bottom trays and pulls the jaw forward to reduce sleep apnea and snoring. Again, this is a bulky device and can also cause the mandible to be pulled forward with a relatively constant force, causing unwanted discomfort of the jaw muscles.
Function regulating devices, such as “Frankel” and “bionator” devices, have been used to treat juvenile malocclusion such as overbite or overjet by gradually adjusting the bite over time. These devices are generally used on children whose jaws are in the process of developing and can be more easily adjusted. This usually corresponds with children ages 8-12, and the devices are typically worn for 12-24 hours at a time. For example, the Function Regulator II (FR-II) was developed by Professor Rolf Frankel of Germany to produce changes in jaw relationships in persons with Class II malocclusion. The Frankel function regulator is a one-piece, removable appliance designed to promote proper dental arch development and jaw relationship during childhood/adolescence. The appliance is intended to work within the vestibule of the mouth and hold away the tissue of the cheeks, lips and chin, allowing the skeletal system to develop in its most natural way.
While such prior art devices may be useful for their intended purposes, they can be quite uncomfortable to wear, causing muscle strain, pain and/or discomfort in the jaw, neck and tongue. Thus, there remains a need for an improved apparatus that is both comfortable to wear and useful for maintaining a patent airway during sleep. It would also be beneficial to provide an intraoral apparatus for treating and correcting upper airway disorders and related problems such as snoring, muscle contraction problems, neck and head pain, obstructive sleep apnea, and other conditions. It would also be beneficial to provide an intraoral device that re-orients and reprograms the muscles of the tongue and mouth in order to establish a new postural performance pattern for the muscles of the face, mouth and neck, so that a more beneficial physiological function of the upper airway can be obtained. There is also a need for a wearable intraoral apparatus that has high patient acceptance and comfort while relieving upper airway disorders and related problems, leading to better treatment success.